title: Predictors for future cystic fibrosis-related diabetes by oral glucose tolerance test.
abstract: BACKGROUND
  An annual oral glucose tolerance test (OGTT) has become part of standard care in cystic fibrosis (CF) to screen for CF-related diabetes (CFRD). The objective of this study was to determine predictors for future CFRD derived from an OGTT.
  
  
  METHODS
  Data were collected from 2001 to 2009 during a longitudinal prospective study on "Early Diagnosis of Diabetes Mellitus in CF Patients, trial number NCT00662714". The 1093 patients included in the analysis had at least two valid OGTTs each and no CFRD at the first glucose challenge. Normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and CFRD were defined using WHO criteria. In a subsample of 521 patients, the NGT group was further divided into patients with a 1-hour glucose level >11.1 mmol/l (indeterminate glucose tolerance -- INDET) and those with a lower level (no-INDET). Logistic regression analysis was used to identify predictors from the first OGTT for future diabetes.
  
  
  RESULTS
  Compared with NGT (n = 838), IFG (n = 70; odds ratio [OR], 95% confidence interval: 2.92, 1.60-5.33) and IGT without IFG (n = 155, OR 2.37, 1.48-3.79) were both significant and independent risk factors for future CFRD. Patients with IGT and IFG (n = 30) had the highest risk (OR 5.30, 2.32-12.10). In the subsample analysis, INDET (n = 116) was associated with a significantly increased risk for future CFRD compared with no-INDET (n = 269; OR 2.81, 1.43-5.51).
  
  
  CONCLUSIONS
  In this large study, IFT, IGT, and INDET were all predictors of future CFRD. The OGTT in patients with CF should include a 1-hour post-challenge value.
authors.affiliation: Children's Hospital, University of Wuerzburg, Josef-Schneider-Strasse 2, 97080 Wuerzburg, Germany. Electronic address: Schmid_K@klinik.uni-wuerzburg.de.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Schmid
authors.affiliation: Institute of Epidemiology and Medical Biometry, University of Ulm, Schwabstrasse 13, 89075 Ulm, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Fink
authors.affiliation: Institute of Epidemiology and Medical Biometry, University of Ulm, Schwabstrasse 13, 89075 Ulm, Germany.
authors.forename: Reinhard W
authors.initials: RW
authors.lastname: Holl
authors.affiliation: Children's Hospital, University of Wuerzburg, Josef-Schneider-Strasse 2, 97080 Wuerzburg, Germany.
authors.forename: Helge
authors.initials: H
authors.lastname: Hebestreit
authors.affiliation: St Josef Hospital Pediatric Clinic, Ruhr University Bochum, Gudrunstrasse 56, 44791 Bochum, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Ballmann
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003550:Cystic Fibrosis / Q000453:epidemiology*; D003920:Diabetes Mellitus / Q000175:diagnosis* / Q000453:epidemiology*; D042241:Early Diagnosis; D005260:Female; D018149:Glucose Intolerance / Q000175:diagnosis / Q000453:epidemiology; D005951:Glucose Tolerance Test; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D017410:Practice Guidelines as Topic; D011236:Prediabetic State / Q000175:diagnosis / Q000453:epidemiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D055815:Young Adult
keywords: Cystic fibrosis; Cystic fibrosis-related diabetes; Oral glucose tolerance test